Nanotribological properties of silicon with silane derived surface modification

Abstract

Silicon substrates were modified with octadecyltrichlorosilane and 3-Aminopropyl-triethoxysilane molecules by chemical adsorption process. The surface properties, morphology and composition were characterised by means of contact angle measurement, atomic force microscopic (AFM) analysis and X-ray photoelectron spectroscopy. To achieve quantitative results, it is important to implement the proper force calibration in AFMs. Both the lateral and the normal spring constants of the AFM cantilever were calibrated. The nanotribological properties including adhesion, friction and antiwear of silane derived surface modification are comparatively studied with the calibrated AFM cantilever. The results demonstrated that the silane derived surface modification reduces adhesion and friction. Hydrophobic methyl terminated modification possesses better friction reduction and antiwear capacity than hydrophilic amine terminated surface.